platformio-vscode-ide: identifier "uint8_t" is undefined

I get all uint8_t and uint16_t declarations marked as errors with identifier "uint8_t" is undefined in my platformio-project for an ESP8266. It can easily be reproduced: Just generate a new project for an esp8266 board, choose arduino as framework and type uint8_t x = 3 somewhere. It will hilight uint8_t and tell its an undefined identifier.

This does not happen on AVR projects for example.

I spend quite some time to debug this issue and found this line be responsible in my c_cpp_properties.json at the includePath array:

           "/home/jan/.platformio/packages/toolchain-xtensa/lib/gcc/xtensa-lx106-elf/4.8.2/include-fixed",

Deleting this fixes the issue.

About this issue

Original URL
State: closed
Created 7 years ago
Comments: 24 (5 by maintainers)

Most upvoted comments

Guys, please open PIO IDE Terminal and type pio upgrade. Starting from PIO Core 3.5.0rc6 we will generate built-in GCC macros for configuration files.

All should work now.

ivankravets on Dec 12, 2017

I’ve done some digging into the stdint.h and limits.h and traced the error down to missing definitions of __SCHAR_MAX__ and __SHRT_MAX__ in the includes-fixed/limits.h. These are defined inside the xtensa gcc and the IntelliSense engine doesn’t find them. The workaround I’ve found is to add

"__SCHAR_MAX__=0x7f",
"__SHRT_MAX__=0x7fff"

to the defines: [ ... ] section of the c_cpp_properties.json file. With this change you can reset the C_Cpp.intelliSenseEngine back to Default without getting the error.

You can print all built-in defines with the following command in Powershell: PS C:\Users\<yourname>\.platformio\packages\toolchain-xtensa\bin> echo $null | .\xtensa-lx106-elf-gcc.exe -dM -E -

DeeFuse on Dec 6, 2017

For me it works. All is good now.

bertmelis on Dec 13, 2017

@Dee-Fuse It sounds like you guys tracked down the missing define. The cpptools extension doesn’t regenerate the c_cpp_properties.json. I think it’s the platformio extension – I think they shouldn’t overwrite an existing c_cpp_properties.json and should rely on users deleting the file if they want the extension to auto-generate a new one.

sean-mcmanus on Dec 6, 2017

Ah, yeah, I also hit this issue. I’ll let you know what I find out…

sean-mcmanus on Dec 2, 2017